[ckan-dev] CKAN and RDF/SPARQL

Wed May 25 15:58:25 UTC 2011

On 25 May 2011 14:44, William Waites <ww at styx.org> wrote:
> * [2011-05-25 10:43:03 +0100] David Read <david.read at okfn.org> écrit:
>
> ] Will, do say if I've not covered all the bases, but I don't think the
> ] way CKAN stores its data internally is an issue for dealing in RDF to
> ] the outside world. We can happily store any RDF properties of a
> ] package in the extra fields, using JSON structures if necessary.
>
> You could do that but it would be really weird. The "RDF properties"
> are already the same properties that a package has.

Sorry I should have been clearer - I'm talking here about package
properties that don't fit in the core package fields. There's not a
problem with the core package fields mapping comfortably to RDF, are
there Will?

And if Ed decides to use any extra fields, can express lists and
dictionaries in our extras fields - they are not limited to string
values. And these can be worked with sanely in CKAN via forms, SOLR,
and (with an extension) the API.

David

> So yes, you
> could cache them in an extras field, but you wouldn't be able to
> query them in any meaningful way.
>
> ] I anticipate Ed wanting customised html for viewing and editing a
> ] package anyway, so that can deal with the extras being stored as lists
> ] etc.. The only extension necessary would be for adding the RDF package
> ] in/out to the API (and D2R sounds useful for this, as well as
> ] providing an SPARQL endpoint). And SOLR's schema would need updating
> ] to cope with these non-textual extra fields.
>
> See above about querying. You need a sane database schema to use
> something like D2R, it won't work if your information is stuffed
> in a JSON-encoded field.
>
> This is not a good idea.
>
> -w
> --
> William Waites                <mailto:ww at styx.org>
> http://river.styx.org/ww/        <sip:ww at styx.org>
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